first question - do you need to advertise the loopbacks for any reason. ( I
know what Cisco says in the training materials, but in fact there may not be
reason to advertise them, and therefore numbering may not matter. )
second question - seeing as Cisco uses loopbacks as the source of RIDs (
router i.d.'s ), which do have significance in a network in some cases,
would you benefit from having a consistent architecture with regards to your
RID's?
In general, good practice would say to use something that could be
summarized out of the router, or at least out of the
area/level/region/whatever. Problem is that using anything from within your
inside block does take up at least an IP address, if not a subnet, depending
upon how you do it.
In my darker moments, I have considered that I may want some kind of
consistent numbering scheme for loopbacks that 1) uniquely identifies that
address as being a loopback address and 2) allows me to easily use that
number to identify the router where is resides.
just a couple of cents.
Chuck
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of
COULOMBE, TROY
Sent: Friday, September 14, 2001 12:31 PM
To: [EMAIL PROTECTED]
Subject: Loopback Address scheme (long) [7:20002]
Alright gang,
Usually I just lurk. However, for those of you doing support for networks,
I would like to know (sample) your loopback address scheme. We have a Hub &
spoke network, with our core network consisting of core services (server
farm, etc) and our two WAN routers. Off these WAN routers are our regions
(and off them branches). Currently there is little redundancy (as far as it
being meshed--we have redundant links/isdn backup, etc). We are a purely
OSPF shop.
So, Core/WAN is Area 0.0.0.0 & Regions/Branches are areas x.x.x.x (Each
(region and their branches) are separate areas...) However, due to
transitions, summarization is not practical (things have moved within the
corp.)
Thoughts on BEST PRACTICE of loopback addressing??? Should I take a /32
from within the major network of each region/branch & use that, or should I
use one class C (and /32 that) and just spread it amongst the sites? Also,
take into consideration that we are moving towards a more partial meshed
network.
Confused? See examples below
Core network:
10.1.0.0 /16 (summarized)
10.1.1.0 /24 (server farm)
Region 1
10.32.0.0 /16 (not summarized)
10.32.1.0 /24 (local net 1)
Branch 1
10.32.1.0 /24 (local net)
Branch 2
10.32.2.0 /24 (local net)
Region 2
10.44.0.0 /16 (not summarized--but in general this is the major
network we are going to)
10.44.1.0 /24 (local net 1)
10.44.2.0 /24 (local net 2)
Branch 1
10.32.7.0 /24 (local net) **** see can't summarize above due
to discontiguous nets ;-< ****
Branch 2
10.44.217.0 /24 (local net)
==========================================================
so solution #1 would be
core network devices use addresses (like)
10.1.2.2 /32 (using a new network here!!!!)
10.1.2.3 /32 (using a new network here!!!!)
etc etc.
Region 1
10.32.2.2 /32 (using a new network here!!!!)
10.32.2.3 /32 (using a new network here!!!!)
Branch 1
10.32.3.2 /32 (using a new network here!!!!)
Branch 2
10.32.4.2 /32 (using a new network here!!!!)
Region 2
10.44.3.2 /32 (using a new network here!!!!)
10.44.3.3 /32 (using a new network here!!!!)
Branch 1
10.32.8.2 /32 (using a new network here!!!!)
Branch 2
10.44.218.2 /32 (using a new network here!!!!)
==========================================================
or solution #2 would be using ONE loopback network...
core network devices use addresses (like)
10.99.99.2 /32
10.99.99.3 /32
etc etc.
Region 1
10.99.99.4 /32
10.99.99.5 /32
Branch 1
10.99.99.6 /32
Branch 2
10.99.99.7 /32
Region 2
10.99.99.8 /32
10.99.99.9 /32
Branch 1
10.99.99.10 /32
Branch 2
10.99.99.11 /32
==============================================================
and maybe I am just sweating the small stuff & it really doesn't
matter...just pondering it, because quite truthfully, I seem to only do
Hub&Spoke OSPF networks...all my mesh/part. mesh networks were EIGRP...
and I figured I'd share this as it might also be a prob/solution that get
peoples minds on off the tragedy.
TroyC
-=-=-=-
With sufficient thrust, pigs fly just fine.
---RFC 1925
Message Posted at:
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